Linkages are a vital mechanism and many examples can
be seen around us. The most common types of linkage are shown below.

REVERSE MOTION LINKAGE:
As the top rod moves to the left the bottom rod moves to the right. The
bars move in opposite directions. Another way of describing this linkage
is the the direction of movement in one rod is reversed in the other
rod. The fixed pivot is the centre of
rotation.

PARALLEL MOTION LINKAGE:
As the large rod at the top of the diagram moves to the left the two
small rods at the bottom move to the right. All the rods are
parallel to each other.
EXAMPLE.

CRANK AND SLIDER LINKAGE:
The rods move forwards and backwards in slider. The fixed pivot anchor
the linkages to one place. EXAMPLE.

BELL CRANK LINKAGE:
This linkage allows horizontal movement to be converted to vertical
movement. It also works the opposite way round. A practical example of
this is the brake mechanism on a bicycle. EXAMPLE.